Bottle

ABSTRACT

There is provided a bottle formed of a synthetic resin material into a cylindrical shape with a bottom, a bottom wall portion of the bottom includes: a ground contact portion which is positioned at an outer circumferential edge portion; a rising peripheral wall portion which is connected to the ground contact portion from an inner side of a bottle radial direction and extends upward; an annular movable wall portion which protrudes from an upper end portion of the rising peripheral wall portion to the inner side of the bottle radial direction; and a depressed peripheral wall portion which extends upward from an inner end portion of the movable wall portion in the bottle radial direction.

TECHNICAL FIELD

The present invention relates to a bottle.

Priority is claimed on Japanese Patent Application No. 2010-240945, filed Oct. 27, 2010, and Japanese Patent Application No. 2010-264169, filed Nov. 26, 2010, the contents of which are incorporated herein by reference.

BACKGROUND ART

As a bottle formed of a synthetic resin material into a cylindrical shape with a bottom, a bottle in which a bottom wall portion of a bottom includes a ground contact portion which is positioned at an outer circumferential edge portion, a rising peripheral wall portion which is connected to the ground contact portion from an inner side of a bottle radial direction and extends upward, a movable wall portion which projects from an upper end portion of the rising peripheral wall portion to an inner side of the bottle radial direction, and a depressed peripheral wall portion which extends upward from an inner end portion of the movable wall portion in the bottle radiation direction, and depressurization in the bottle is absorbed by causing the movable wall portion to revolve about a connecting portion with the rising peripheral wall portion so as to move the depressed peripheral wall portion upward as disclosed in Patent Document 1, for example, has been conventionally known.

CITATION LIST Patent Document

[Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2010-126184

SUMMARY OF INVENTION Technical Problem

According to the conventional bottle, however, there is a room for improvement of a performance of absorbing depressurization in the bottle.

Thus, the present invention was made in consideration of the above circumference, and an object thereof is to provide a bottle capable of improving a performance of absorbing depressurization in the bottle.

Solution to Problem

In order to achieve the above object, the present invention provides the following means.

(1) The bottle according to an embodiment of the present invention is a bottle formed of a synthetic resin material into a cylindrical shape with a bottom, a bottom wall portion of the bottom including: a ground contact portion which is positioned at an outer circumferential edge portion; a rising peripheral wall portion which is connected to the ground contact portion from an inner side of a bottle radial direction and extends upward; an annular movable wall portion which protrudes from an upper end portion of the rising peripheral wall portion to the inner side of the bottle radial direction; and a depressed peripheral wall portion which extends upward from an inner end portion of the movable wall portion in the bottle radial direction, wherein the movable wall portion is disposed so as to freely revolve about a connecting portion with the rising peripheral wall portion so as to move the depressed peripheral wall portion upward, wherein the rising peripheral wall portion extends so as to gradually incline to the inner side of the bottle radial direction from the ground contact portion to the connecting portion with the movable wall portion, and an inclination angle thereof is an angle of equal to or greater than 0° and less than 20° with respect to a bottle axis, and wherein the height from the ground contact portion to the connecting portion between the rising peripheral wall portion and the movable wall portion is equal to or greater than 3.5 mm and less than or equal to 7.5 mm.

According to the bottle of the embodiment of the present invention, it is possible to absorb depressurization by moving the depressed peripheral wall portion upward by revolving the movable wall portion during the depressurization in the bottle. Incidentally, the movable wall portion is considered to revolve about the connecting portion with the rising peripheral wall portion due to an increase in diameter caused by the upper end portion of the rising peripheral wall portion moving to the outer side in the bottle radial direction.

Here, according to the bottle of the embodiment of the present invention, the rising peripheral wall portion inclines to the inner side of the bottle radial direction within the above inclination angle range with respect to the bottle axis when approaching the connecting portion with the movable wall portion, and the height from the ground contact portion to the connecting portion is set within the above height range. Therefore, the rising peripheral wall portion is considered to be designed such that the upper end portion as the connecting portion with the movable portion flexibly and easily moves in the bottle radial direction from the ground contact portion as a base point and the upper end portion thus easily moves to the outer side of the bottle radial direction during the depressurization.

Accordingly, it is possible to cause the movable wall portion to sensitively follow variations in the inner pressure in the bottle and flexibly revolve and to thereby improve the performance of absorbing depressurization.

In addition, it is considered that the upper end portion of the rising peripheral wall portion does not easily move in the bottle radial direction while the ground contact portion positioned on a side of a lower end portion of the rising peripheral wall portion easily moves in the bottle radial direction when the inclination angle of the rising peripheral wall portion is equal to or greater than 20° and the height from the ground contact portion to the connecting portion between the rising peripheral wall portion and the movable wall portion is less than 3.5 mm. Therefore, the ground contact portion easily moves to the further outer side than the upper end portion of the rising peripheral wall portion in the bottle radial direction during the depressurization, and there is a concern that the revolving motion of the movable wall portion is inhibited.

(2) In the bottle according to the embodiment of the present invention, the movable wall portion extends so as to gradually incline downward from the connecting portion with the rising peripheral wall portion to the inner side of the bottle radial direction, and an angle between the movable wall portion and the rising peripheral wall portion is equal to or greater than 60° and less than or equal to 85°.

In such a case, since the angle between the movable wall portion and the rising peripheral wall portion is within the above range, the aforementioned advantageous effect can be significantly displayed, that is, it is possible to cause the movable wall portion to sensitively follow variations in the inner pressure in the bottle and flexibly rotate and to thereby improve the performance of absorbing depressurization. In addition, since the movable wall portion extends so as to gradually incline downward from the connecting portion with the rising peripheral wall portion to the inner side of the bottle radial direction, it is easy to revolve the movable wall portion downward during the filling of the bottle with a substance. Therefore, it is possible to increase the depressurization absorbing capacity immediately after the filling by increasing the volume of the bottle and to thereby further improve the performance of absorbing depressurization.

(3) In the bottle according to the embodiment of the present invention, the movable wall portion extends so as to gradually incline downward from an outer end portion connected to the rising peripheral wall portion to an inner end portion connected to the depressed peripheral wall portion, and the height from the ground contact portion to the inner end portion of the movable wall portion is 45% or less of the height from the ground contact portion to the outer end portion of the movable wall portion.

According to the bottle of the embodiment of the present invention, it is possible to absorb depressurization by moving the depressed peripheral wall portion upward by revolving the movable wall portion during the depressurization in the bottle. Particularly, since the movable wall portion extends so as to gradually incline downward from the outer end portion to the inner end portion and the height from the ground contact portion to the inner end portion is 45% or less of the height from the ground contact portion to the outer end portion to secure a great height difference between the outer end portion and the inner end portion, it is easy to revolve the movable wall portion downward during the filling of the bottle with a substance. Therefore, it is possible to increase the depressurization absorbing capability immediately after the filling by increasing the volume of the bottle and to thereby improve the performance of absorbing depressurization.

(4) In the bottle according to the embodiment of the present invention, the height of the inner end potion of the movable wall portion from the ground contact portion may be equal to or greater than 2 mm.

In such a case, the inner end portion does not easily project further downward than the ground contact portion when the movable wall portion revolves downward during the filling of the content, and it is possible to easily avoid contact with the ground contact surface. Accordingly, it is possible to reliably perform the filling operation while suppressing the projection of the inner end portion of the movable wall portion even in the case of high-temperature filling, for example.

Advantageous Effects of Invention

According to a bottle of an embodiment of the present invention, it is possible to improve the performance of absorbing depressurization in the bottle.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a bottle according to an embodiment of the present invention.

FIG. 2 is a bottom view of the bottle shown in FIG. 1.

FIG. 3 is a cross-sectional view of the bottle taken along the line A-A shown in FIG. 2.

FIG. 4 is a cross-sectional view of the bottle taken along the line B-B shown in FIG. 2.

FIG. 5 is a bottom view of a bottle according to a modified example of the embodiment of the present invention.

FIG. 6 is a cross-sectional view of the bottle taken along the line C-C shown in FIG. 5.

FIG. 7 is a side view of a bottle according to an embodiment of the present invention.

FIG. 8 is a bottom view of the bottle shown in FIG. 7.

FIG. 9 is a cross-sectional view of the bottle take along the line A-A shown in FIG. 8.

FIG. 10 is a bottom view of a bottle according to a modified example of the embodiment of the present invention.

FIG. 11 is a cross-sectional view of the bottle taken along the line B-B shown in FIG. 10.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a description will be given of a bottle according to an embodiment of the present invention with reference to the drawings.

A bottle 1 according to the embodiment includes a mouth portion 11, a shoulder portion 12, a body portion 13, and a bottom 14 as shown in FIGS. 1 to 4 and is substantially configured such that these components are sequentially provided in this order while the respective center axis lines are positioned on a common axis.

Hereinafter, the common axis is referred to as a bottle axis O, the side of the mouth portion 11 in the direction of the bottle axis O is referred to as an upper side, and the side of the bottom 14 is referred to as a lower side. In addition, a direction which is perpendicular to the bottle axis O is referred to as a bottle radial direction, and a direction revolving about the bottle axis O is referred to as a bottle circumferential direction.

In addition, the bottle 1 is formed by blow-molding a pre-form which has been formed into a cylindrical shape with a bottom by injection molding and is integrally formed of a synthetic resin material. In addition, a cap which is not shown in the drawings is threadably mounded to the mouth portion 11. Moreover, the horizontal cross-sectional shapes of the mouth portion 11, the shoulder portion 12, the body portion 13, and the bottom 14 which are perpendicular to the bottle axis O are all circular in shape.

A first annular concave groove 15 is continuously formed over the entire circumference of a part between the shoulder portion 12 and the body portion 13.

The body portion 13 is formed into a cylindrical shape to have a smaller diameter than the diameters of the lower end portion of the shoulder portion 12 and the heel portion 17 of the bottom 14 which will be described later. A plurality of second annular concave grooves 16 are formed on the body portion 13 at intervals in the direction of the bottle axis O. In the example shown in the drawing, four second annular concave grooves 16 are formed at equal intervals in the direction of the bottle axis O. Each of the second annular concave grooves 16 is a groove portion which is continuously formed over the entire circumference of the body portion 13.

The bottom 14 is formed into a cup shape and includes a heel portion 17 with an upper end opening portion which is connected to the lower end opening portion of the body portion 13 and a bottom wall portion 19 which blocks the lower end opening portion of the heel portion 17 and includes a ground contact portion 18 at the outer circumferential edge portion.

In the heel portion 17, a heel lower end portion 27 which is connected to the ground contact portion 18 from the outer side of the bottle radial direction is formed to have a smaller diameter than the diameter of an upper heel portion 28 connected to the heel lower end portion 27 from the upper side.

Both the upper heel portion 28 and the lower end portion of the shoulder portion 12 have the maximum outer diameter in the bottle 1.

In addition, the diameter of a coupling part 29 between the heel lower end portion 27 and the upper heel portion 28 is gradually reduced from the upper side to the lower side, and thus, the diameter of the heel lower end portion 27 is smaller than the diameter of the upper heel portion 28. A third annular concave groove 20 with approximately the same depth as that of the above second annular concave groove 16 is continuously formed over the entire circumference of the upper heel portion 28.

As shown in FIG. 3, the bottom wall portion 19 includes a rising peripheral wall portion 21 connected to the ground contact portion 18 from the inner side of the bottle radial direction and extending upward, an annular movable wall portion 22 projecting from the upper end portion of the rising peripheral wall portion 21 to the inner side of the bottle radial direction, and a depressed peripheral wall portion 23 extending upward from the inner end portion of the movable wall portion 22 in the bottle radial direction.

The movable wall portion 22 is formed into a curved surface shape which protrudes downward and extends so as to gradually incline downward from the outer side to the inner side of the bottle radial direction. The movable wall portion 22 and the rising peripheral wall portion 21 are coupled via a curved surface portion 25 which protrudes upward. In addition, the movable wall portion 22 is designed to be freely revolved about the curved surface portion (the connecting part with the rising peripheral wall portion 21) 25 so as to cause the depressed peripheral wall portion 23 to move upward.

In addition, an annular bottom (the movable wall portion 22 and the depressed peripheral wall portion 23) formed between the upper end of the rising peripheral wall portion 21 and an outer edge of an apex wall 24 disposed above the upper end of the rising peripheral wall portion 21 is formed into a substantially U shape (substantially V shape or substantially L shape) in a vertical half cross-sectional view so as to expand downward over the entire circumference.

The diameter of the rising peripheral wall portion 21 is gradually reduced from the lower side to the upper side. Specifically, the rising peripheral wall portion 21 extends so as to gradually incline to the inner side of the bottle radial direction from the ground contact portion 18 to the curved surface portion 25 which is a connecting portion with the movable wall portion 22, and the inclination angle θ1 is set to 10°, for example, within an angular range of equal to or greater than 0° and less than 20° with respect to the bottle axis O.

In addition, a height T from the ground contact portion 18 to the curved surface portion 25 is set to 5 mm, for example, within a height range of equal to or greater than 3.5 mm and less than or equal to 7.5 mm in this embodiment. Moreover, an angle θ2 between the movable wall portion 22 and the rising peripheral wall portion 21 is set to 73°, for example, within an angular range of equal to or greater than 60° and less than or equal to 85°.

As shown in FIGS. 2 and 4, a plurality of ribs 40 are radially disposed about the bottle axis O in the bottle wall portion 22. That is, the respective ribs 40 are disposed at uniform intervals in the bottle circumferential direction.

In the example shown in the drawings, the ribs 40 are configured such that a plurality of concave portions 40 a depressed upward in the curved surface shapes intermittently and linearly extend along the bottle radial direction. In so doing, the ribs 40 have a wave form in a vertical cross-sectional view along the bottle radial direction.

The respective concave portions 40 a are formed into a same size and a same shape and are arranged at equal intervals along the bottle radial direction. In addition, the respective positions, at which the plurality of concave portions 40 a are disposed, in the bottle radial direction are the same in each of the plurality of ribs 40.

In addition, a concave portion 40 a at the outermost position in the bottle radial direction among the plurality of concave portions 40 a in the respective ribs 40 is proximate to the curved surface portion 25 from the inner side of the bottle radial direction, and a concave portion 40 a at the innermost position in the bottle radial direction is proximate to the depressed peripheral wall portion 23 from the outer side of the bottle radial direction.

The depressed peripheral wall portion 23 is coaxially disposed with the bottle axis O as shown in FIG. 3, and is formed into a circular shape in the horizontal cross-sectional view such that the diameter thereof gradually increases from the upper side to the lower side. A disc-shaped apex wall 24 which is coaxially arranged with the bottle axis O is connected to the upper end portion of the depressed peripheral wall portion 23, and the depressed peripheral wall portion 23 and the apex wall 24 form a cylindrical shape with an apex as a whole.

The depressed peripheral wall portion 23 is formed into a curved surface shape which protrudes to the inner side of the bottle radial direction, and the upper end portion includes a curved wall portion 23 a which is sequentially provided at the outer circumferential edge portion of the apex wall 24. The lower end portion of the curved wall portion 23 a is sequentially provided at the inner end portion of the movable wall portion 22 in the bottle radial direction via the curved surface portion 26 which protrudes downward.

If the inside of the bottle 1 configured as described above is depressurized, the movable wall portion 22 revolves upward about the curved surface portion 25 of the bottom wall portion 19 such that the movable wall portion 22 moves to lift the depressed peripheral wall portion 23 upward. That is, it is possible to absorb variations in the inner pressure (depressurization) in the bottle 1 by actively deforming the bottom wall portion 19 of the bottle 1 during depressurization.

Incidentally, it is considered that the movement of the upper end portion of the rising peripheral portion 21 to the outer side of the bottle radial direction causes the movable wall portion 22 to revolve about the curved surface portion 25 which is a connecting portion with the rising peripheral portion 21 during depressurization.

Here, in the bottle 1 according to the embodiment, the rising peripheral wall portion 21 inclines to the inner side of the bottle radial direction at the inclination angle θ1 with respect to the bottle axis O as the rising peripheral wall portion 21 approaches the curved surface portion 25, the height from the ground contact portion 18 to the curved surface portion 25 is set to the above height T, and further, the angle between the rising peripheral wall portion 21 and the movable wall portion 22 is set to the above angle θ2.

Therefore, it is considered that the upper end portion of the rising peripheral wall portion 21, which is the connecting portion with the movable wall portion 22, can easily and flexibly move in the bottle radial direction from the ground contact portion 18 as a based point, and therefore, the upper end portion can easily moves to the outer side of the bottle radial direction during the depressurization. Accordingly, it is possible to cause the movable wall portion 22 to sensitively follow the variations in the inner pressure in the bottle 1 and flexibly revolve and enhance the performance of absorbing depressurization.

In addition, since the movable wall portion 22 extends so as to gradually incline downward from the curved surface portion 25 as the connecting portion with the rising peripheral wall portion 21 to the inner side of the bottle radial direction, it is easy to cause the movable wall portion 22 to revolve downward during filling of the bottle with a substance. Therefore, it is possible to enhance the depressurization absorbing capacity immediately after the filling by increasing a volume in the bottle 1 and to thereby further easily improve the performance of absorbing depressurization.

In addition, since the plurality of ribs 40 are formed on the movable portion 22 of the bottom wall portion 19, it is possible to increase a pressure receiving area by increasing the surface area of the movable wall portion 22 and to rapidly deform the movable wall portion 22 according to variations in the inner pressure in the bottle 1.

The bottle 1 according to the embodiment is suitable for a bottle with a volume of 1 liter or less and with a ground contact diameter of 85 mm or less.

In addition, the technical scope of the present invention is not limited to the embodiment, and various modifications can be made without departing from the gist of the present invention.

For example, although the ribs 40 intermittently and radially extend in the above embodiment, the present invention is not limited thereto, and the ribs 40 may continuously extend or extend while curved. In addition, the design of the shape and the size of the concave portions 40 a can be appropriately changed. Moreover, the ribs 40 are not essential and may not be provided.

In addition, a concave and convex portion 41 may be formed over the entire circumference of the rising peripheral wall portion 21 as shown in FIGS. 5 and 6. In addition, the concave and convex portion 41 is configured by disposing a plurality of convex portions 41 a formed into curved surface shapes which protrude to the inner side of the bottle radial direction at intervals in the bottle circumferential direction.

By forming the concave and convex portion 41 as described above, feeling of incongruity is not easily given when the bottom 14 of the bottle 1 filled with content is viewed since light which is incident on the rising peripheral wall portion 21 is diffusely reflected by the concave and convex portion 41 or the concave and convex portion 41 is also filled with the substance in the bottle 1, for example.

Although the angle θ2 between the rising peripheral wall portion 21 and the movable wall portion 22 is configured to be within an angular range of equal to or greater than 60° and less than or equal to 85° in the embodiment, the present invention is not limited to the angular range. For example, the movable wall portion 22 may be appropriately changed so as to project in parallel with the bottle radial direction or incline upward, for example, or may be appropriately changed so as to be formed into a planer shape or a concave curved surface shape which is depressed upward.

However, it is preferable that the angle θ2 between the rising peripheral wall portion 21 and the movable wall portion 22 be within the angular range of not equal to or great than 60° and less than or equal to 85° and that the movable wall portion 22 incline downward as in the embodiment. In so doing, the revolution property of the movable wall portion 22 is enhanced, and it is easy to improve the performance of absorbing depressurization.

Although the rising peripheral wall portion 21 and the movable wall portion 22 are connected to each other via the curved surface portion 25 in the embodiment, a configuration is also applicable in which an annular concave portion which is depressed upward with respect to a virtual line extended to the outer side of the bottle radial direction along the line of the surface shape of the movable wall portion 22 is formed at the connecting portion and the movable wall portion 22 freely revolves about the annular concave portion. In such a case, it is possible to expect a high hinge effect by providing flexibility to the outer end portion of the movable wall portion 22 in the radial direction to thereby cause the movable wall portion 22 to further sensitively follow the variations in the inner pressure in the bottle 1 and flexibly deform the movable wall portion 22 and further improve the performance of absorbing depressurization in the bottle 1.

In addition, even in the case in which the annular concave groove is formed, it is preferable that the angle between the rising peripheral wall portion 21 and the movable wall portion 22, more specifically, the angle θ2 between the rising peripheral wall portion 21 and the virtual line be within the angular range of equal to or greater than 60° and less than or equal to 85°.

In addition, although each of the horizontal cross-sectional shapes of the shoulder portion 12, the body portion 13, and the bottom 14, which is perpendicular to the bottle axis O, is a circular shape in the embodiment, the horizontal cross-sectional shape is not limited thereto and may be appropriately changed to a polygonal shape or the like, for example.

In addition, the synthetic resin material forming the bottle 1 may be appropriately changed to polyethylene terephthalate, polyethylene naphthalate, amorphous polyester, or a blend material thereof. Furthermore, the bottle 1 may be formed into a laminated structure with an intermediate layer as well as a single layer structure. In addition, examples of the intermediate layer include a layer formed of a resin material with a gas barrier property, a layer formed of a recycled material, a layer formed of a resin material with an oxygen absorption property, and the like.

EXAMPLES

Next, description will be given of an example of a test (analysis) for observing how a relationship between depressurization intensity (kPa) and depressurization absorbing volume (ml) changes when the inclination angle θ1 of the rising peripheral wall portion 21, and the height T from the ground contact portion 18 to the curved surface portion 25 are respectively changed.

In addition, the test was performed using the bottle 1 shown in FIGS. 1 to 4, in which the plurality of ribs 40 were formed in the movable wall portion 22.

The test was performed by preparing a total of four patterns, namely a first pattern with the inclination angle θ1 of 5° and with the height T of 3.5 mm, a second pattern with the inclination angle θ1 of 10° and with the height T of 3.5 mm, a third pattern with the inclination angle θ1 of 15° and with the height T of 3.5 mm, and a comparison pattern with the inclination angle θ1 of 20° and the height T of 3.5 mm.

As a result, it was confirmed that a depressurization absorbing capacity increased in an initial stage in which an increase in the depressurization intensity was started in any of the four patterns. This is considered to be because the entire bottom wall portion 19 moved upward due to the depressurization in the bottle 1.

However, it was confirmed that the depressurization absorbing capacity steeply increased at later timing at which the depressurization intensity further increased and reached about 10 (kPa) in the first to third patterns. This is considered to be because the movable wall portion 22 smoothly revolved and inversely deformed and the depressed peripheral wall portion 23 was thus moved upward since the inclination angle θ1 was within the angular range of equal to or greater than 0° and less than 20° and the height T was in the height range of equal to or greater than 3.5 mm and less than or equal to 7.5 mm.

On the other hand, the steep increase phenomenon of the depressurization absorbing capacity due to the inverse deformation of the movable wall portion 22 was not observed in the case of the comparison pattern even when the depressurization intensity was further increased.

In addition, it was similarly confirmed that the depressurization absorbing capacity steeply increased at the timing at which the depressurization intensity reached about 10 (kPa) even when the height T was set to 5.0 mm instead of 3.5 mm and the inclination angle θ1 was set to 5°, 10°, 15°, and 20° in the first to third patterns.

Furthermore, the same change was confirmed even when the height T was set to 7.5 mm and the inclination angle θ1 was set to 5°, 10°, 15°, and 20°. In addition, the steep increase phenomenon of the depressurization absorbing capacity was observed in the above height range even when the inclination angle θ1 was set to 0°.

However, there is a problem that it is difficult to shape the bottle if the inclination angle θ1 is set to less than 0° (negative).

Based on the above, it was confirmed that the movable wall portion 22 was flexibly deformed and the performance of absorbing depressurization was improved by setting the inclination angle θ1 of the rising peripheral wall portion 22 within the angular range of equal to or greater than 0° to less than 20° and setting the height T from the ground contact portion 18 to the curved surface portion 25 within the height range of equal to or greater than 3.5 mm to less than or equal to 7.5 mm.

Hereinafter, a description will be given of a bottle according to a second embodiment of the present invention referring to FIGS. 7 to 9. In the description of the second embodiment, the same reference numerals as those in the first embodiment will be used for the same configuration as those in the first embodiment, and a description thereof will be omitted here.

As shown in FIG. 7, the bottom 140 of the bottle 10 according to the embodiment is formed into a cup shape and includes a heel portion 170 at which an upper end opening portion of the bottom 140 is connected to the lower end opening portion of the body portion 13 and a bottom wall portion 190 which blocks the lower end opening portion of the heel portion 170 and includes a ground contact portion 180 at the outer circumferential edge portion.

In the heel portion 170, a heel lower end portion 270 which is connected to the ground contact portion 180 from the outer side of the bottle radial direction is formed to have a smaller diameter than the diameter of an upper heel portion 280 connected to the heel lower end portion 270 from the upper side.

Both the upper heel portion 280 and both end portions of the body portion 13 in the direction of the bottle axis O have the maximum outer diameter in the bottle 10.

In addition, the diameter of a coupling part 290 between the heel lower end portion 270 and the upper heel portion 280 is gradually reduced from the upper side to the lower side, and thus, the diameter of the heel lower end portion 270 is smaller than the diameter of the upper heel portion 280. A fourth annular concave groove 310 with approximately the same depth as that of the third annular concave groove 20 is continuously formed over the entire circumference of the upper heel portion 280.

As shown in FIG. 9, the bottom wall portion 190 includes a rising peripheral wall portion 210 connected to the ground contact portion 180 from the inner side of the bottle radial direction and extending upward, an annular movable wall portion 220 projecting from the upper end portion of the rising peripheral wall portion 210 to the inner side of the bottle radial direction, and a depressed peripheral wall portion 230 extending upward from the inner side of the movable wall portion 220 in the bottle radial direction.

The ground contact portion 180 is in annular line contact, for example, with a ground contact surface G. The diameter of the rising peripheral wall portion 210 is gradually reduced from the lower side to the upper side.

The movable wall portion 220 is formed into a curved surface shape which protrudes downward, and extends so as to gradually incline downward from the outer end portion connected to the rising peripheral wall portion 210 to the inner end portion connected to the depressed peripheral wall portion 230.

In the embodiment, the movable wall portion 220 and the rising peripheral wall portion 210 are coupled to each other via a curved surface portion 250 which protrudes upward, and the movable wall portion 220 and the depressed peripheral wall portion 230 are coupled to each other via a curved surface portion 260 which protrudes downward.

Therefore, the curved surface portion 250 functions as an outer end portion of the movable wall portion 220, and the curved surface portion 260 functions as an inner end portion of the movable wall portion 220.

In addition, the movable wall portion 220 is designed to freely revolve about the curved surface portion 250, which is the outer end portion of the movable wall portion 220, so as to move the depressed peripheral wall portion 230 upward.

In addition, the curved surface portion 250, which is the outer end portion of the movable wall portion 220, and the curbed surface portion 260, which is the inner end portion of the movable wall portion 220, are separate from the ground contact surface G.

On this occasion, a height H1 from the ground contact surface G along which the ground contact portion 180 is in contact with the ground to the curve surface portion 260, which is the inner end portion of the movable wall portion 220, is set to equal to or greater than 2 mm which is 45% or less of a height H2 from the ground contact surface G to the curved surface portion 250, which is the outer end portion of the movable wall portion 220.

The depressed peripheral wall portion 230 is coaxially disposed with the bottle axis O and is formed into multiple stages such that the diameter thereof gradually increases from the upper side to the lower side. A disc-shaped apex wall 240 which is coaxially arranged with the bottle axis O is connected to the upper end portion of the depressed peripheral wall portion 230, and the depressed peripheral wall portion 230 and the apex wall 240 form a cylindrical shape with an apex as a whole.

The depressed peripheral wall portion 230 according to the embodiment includes a lower cylindrical portion 230 a with a diameter which gradually decreases from the inner end portion of the movable wall portion 220 in the bottle radial direction to the upper side, an upper cylindrical portion 230 b, which includes an upper end potion coupled to the outer circumferential edge portion of the apex wall 240, the diameter of which gradually increases when approaching downward, which is formed into a curbed surface shape protruding downward, and a stage portion 230 c which couples both the cylindrical portions 230 a and 230 b, and the depressed peripheral wall portion 230 is formed into a two-stage cylindrical shape.

The lower cylindrical portion 230 a is formed into a circular shape in the horizontal cross-sectional view and is coupled to the movable wall portion 220 via the curved surface portion 260. Projecting parts 230 d which project to the inner side of the bottle radial direction are formed in the upper cylindrical portion 230 b. The projecting portions 230 d are formed over the entire length of the upper cylindrical portion 230 b in the direction of the bottle axis O other than the upper end portion, and a plurality of projecting portions 230 d are sequentially formed in the bottle circumferential direction as shown in FIG. 8.

In the example shown in the drawing, projecting portions 230 d which are adjacent in the bottle circumferential direction are arranged at intervals in the bottle circumferential direction.

In addition, the horizontal cross-sectional shape of the upper cylindrical portion 230 b is deformed from a polygonal shape to a circular shape from the lower side to the upper side by forming the projecting portions 230 d, and the horizontal cross-sectional shape of the upper cylindrical portion 230 b at the upper end portion is a circular shape.

At a part at which the horizontal cross-sectional shape is a polygonal shape in the upper cylindrical portion 230 b, the projecting portions 230 d correspond to sides of the polygonal shape, and interposed parts 230 e positioned between adjacent projecting portions 230 d in the bottom circumferential direction correspond to corners of the polygonal shape.

Although a case in which the polygonal shape is a substantially equilateral triangle is exemplified in the drawing, the present invention is not limited to the case.

If the inside of the bottle 10 configured as described above is depressurized, the movable wall portion 220 revolves upward about the curved surface portion 250 such that the movable wall portion 220 moves to lift the depressed peripheral wall portion 230 upward. That is, it is possible to absorb variations in the inner pressure (depressurization) in the bottle 10 by actively deforming the bottom wall portion 190 of the bottle 10 during the depressurization.

Particularly, since the movable wall portion 220 extends so as to gradually incline downward from the curved surface portion 250, which is the outer end portion of the movable wall portion 220, to the curved surface portion 260, which is the inner end portion of the movable wall portion 220, and the height H1 from the ground contact surface G to the curved surface portion 260, which is the inner end portion of the movable wall portion 220, is 45% or less of the height H2 from the ground contact surface G to the curved surface portion 250, which is the outer end portion of the movable wall portion 220, to secure a large height difference, it is easy to cause the movable wall portion 220 to revolve downward during filling of content. Therefore, it is possible to enhance the depressurization absorbing capacity immediately after the filling by increasing the volume of the bottle 10 and to thereby improve the performance of absorbing depressurization.

Furthermore, since the curved surface portion 260, which is the inner end portion of the movable wall portion 220, is separate from the ground contact surface G by equal to or greater than 2 mm, the curved surface portion 260 does not easily project further downward than the ground contact portion 180 when the movable wall portion 220 revolves downward during filling of content, and contact with the ground contact surface G can be easily avoided. Accordingly, it is possible to reliably perform the filling operation while suppressing the projection of the curved surface portion 260 even in the case of a high-temperature filling.

Although a case in which the curved surface portion 260, which is the inner end portion of the movable wall portion 220, is the lowermost end potion which is the closest to the ground contact surface G in the movable wall portion 220 is exemplified in the embodiment, a case in which a substantially intermediate part of the bottle radial direction corresponds to the lowermost end portion can be also considered depending on the shape of the movable wall portion 220. In such a case, the height to the lowermost portion is H1.

In addition, the bottle 10 according to the embodiment is suitable for a bottle with a volume of 1 liter or less and with a ground contact diameter of 85 mm or less, which is used when filling the bottle with the substance at 75° C. or lower (more specifically, a temperature range from 60° C. to 75° C.).

In addition, the technical scope of the present invention is not limited to the embodiment, and various modifications can be made without departing from the gist of the present invention.

As shown in FIGS. 10 and 11, a plurality of ribs 400 may be radially formed about the bottle axis O in the bottle wall portion 220 in the embodiment. That is, the respective ribs 400 are disposed at uniform intervals in the bottle circumferential direction.

In the example shown in the drawings, the ribs 400 are configured such that a plurality of concave portions 400 a depressed upward in the curved surface shapes intermittently and linearly extend along the bottle radial direction and the ribs 400 are formed into a wave form in a vertical cross-sectional view along the bottle radial direction. In addition, the respective concave portions 400 a are formed into the same size and the same shape and are arranged at equal intervals along the bottle radial direction. In addition, the respective positions, at which the plurality of concave portions 400 a are disposed, in the bottle radial direction are the same in each of the plurality of ribs 400.

By forming the plurality of ribs 400 in the movable portion 220 as described above, it is possible to increase a pressure receiving area by increasing a surface area of the movable wall portion 220 and to thereby rapidly deform the movable wall portion 220 according to variations in the inner pressure in the bottle 10.

Furthermore, a concave and convex portion 410 may be formed over the entire circumference of the rising peripheral wall portion 210 as shown in FIGS. 10 and 11. In addition, the concave and convex portion 410 is configured by disposing a plurality of convex portions 410 a formed into curved surface shapes which protrude to the inner side of the bottle radial direction at intervals in the bottle circumferential direction.

By forming the concave and convex portion 410 as described above, feeling of incongruity is not easily given when the bottom 140 of the bottle 10 filled with content is viewed since light which is incident on the rising peripheral wall portion 210 is diffusely reflected by the concave and convex portion 410 or the concave and convex portion 410 is also filled with the substance in the bottle 10, for example.

In the embodiment, the rising peripheral wall portion 210 may be appropriately changed so as to extend in parallel with the direction of the bottle axis O, for example. In addition, the movable wall portion 220 may be appropriately changed so as to be formed into a planar shape or a concave curved surface shape which is depressed upward, for example.

Although the upper cylindrical portion 230 b is formed into a curved surface shape which protrudes downward in this embodiment, the present invention is not limited to this shape.

In addition, the adjacent projecting portions 230 d in the bottle circumferential direction are arranged at intervals in the bottle circumferential direction in this embodiment, however, the present invention is not limited thereto, and the projecting portions 230 d may be arranged without any interval in the bottle circumferential direction and directly coupled to each other. In such a case, the horizontal cross-sectional shape of the upper cylindrical portion 230 b on a part where the projecting portions 230 d are arranged may be a circular shape, or the horizontal cross-sectional shape of the upper cylindrical portion 230 b may be a circular shape over the entire length in the direction of the bottle axis O.

In addition, the projecting portions 230 d are not essential and may not be provided. Furthermore, although the depressed peripheral wall portion 230 is formed into a two-stage cylindrical shape, the depressed peripheral wall portion 230 may be formed into a cylindrical shape with three or more stages or may not be formed into a multi-stage shape.

In addition, the synthetic resin material forming the bottle 10 may be appropriately changed to polyethylene terephthalate, polyethylene naphthalate, amorphous polyester, or a blend material thereof. Furthermore, the bottle 10 may be formed into a laminated structure with an intermediate layer as well as a single layer structure. In addition, examples of the intermediate layer include a layer formed of a resin material with a gas barrier property, a layer formed of a recycled material, a layer formed of a resin material with an oxygen absorption property, and the like.

In addition, although each of the horizontal cross-sectional shapes of the shoulder portion 12, the body portion 13, and the bottom 14, which is perpendicular to the bottle axis O, is a circular shape in this embodiment, the horizontal cross-sectional shape is not limited thereto and may be appropriately changed to a polygonal shape or the like, for example.

INDUSTRIAL APPLICABILITY

According to the bottle of the embodiments of the present invention, it is possible to improve the performance of absorbing depressurization in the bottle.

REFERENCE SIGNS LIST

-   O: Bottle Axis -   T: Height from Ground Contact Portion to Curved Surface Portion -   θ1: Inclination Angle of Rising Peripheral Wall Portion -   θ2: Angle Between Movable Wall Portion and Rising Peripheral Wall     Portion -   1: Bottle -   12: Shoulder Portion -   18: Ground Contact Portion -   19: Bottom Wall Portion of Bottom -   21: Rising Peripheral Wall Portion -   22: Movable Wall Portion -   23: Depressed Peripheral Wall Portion -   25: Curved Surface Portion (Connecting Portion Between Movable Wall     Portion and Rising Peripheral Wall Portion) -   10: Bottle -   140: Bottom -   180: Ground Contact Portion -   190: Bottom Wall Portion of Bottom -   210: Rising Peripheral Wall Portion -   220: Movable Wall Portion -   230: Depressed Peripheral Wall Portion -   250: Curved Surface Portion (Outer End Portion of Movable Wall     Portion) -   260: Curved Surface Portion (Inner End Portion of Movable Wall     Portion) 

1. A bottle formed of a synthetic resin material into a cylindrical shape with a bottom, a bottom wall portion of the bottom comprising: a ground contact portion which is positioned at an outer circumferential edge portion; a rising peripheral wall portion which is connected to the ground contact portion from an inner side of a bottle radial direction and extends upward; an annular movable wall portion which protrudes from an upper end portion of the rising peripheral wall portion to the inner side of the bottle radial direction; and a depressed peripheral wall portion which extends upward from an inner end portion of the movable wall portion in the bottle radial direction, wherein the movable wall portion is disposed so as to freely revolve about a connecting portion with the rising peripheral wall portion so as to move the depressed peripheral wall portion upward, the rising peripheral wall portion extends so as to be gradually reduced in diameter to the inner side of the bottle radial direction from the ground contact portion to the connecting portion with the movable wall portion, and an inclination angle thereof is an angle of equal to or greater than 0° and less than 20° with respect to a bottle axis, and a height from the ground contact portion to the connecting portion between the rising peripheral wall portion and the movable wall portion is equal to or greater than 3.5 mm and less than or equal to 7.5 mm.
 2. The bottle according to claim 1, wherein the movable wall portion extends so as to gradually incline downward from the connecting portion with the rising peripheral wall portion to the inner side of the bottle radial direction, and wherein an angle between the movable wall portion and the rising peripheral wall portion is equal to or greater than 60° and less than or equal to 85°.
 3. The bottle according to claim 1, wherein the movable wall portion extends so as to gradually incline downward from an outer end portion connected to the rising peripheral wall portion to an inner end portion connected to the depressed peripheral wall portion, and a height from the ground contact portion to the inner end portion of the movable wall portion is 45% or less of a height from the ground contact portion to the outer end portion of the movable wall portion.
 4. The bottle according to claim 3, wherein a height of the inner end potion of the movable wall portion from the ground contact portion is equal to or greater than 2 mm.
 5. The bottle according to claim 2, wherein the movable wall portion extends so as to gradually incline downward from an outer end portion connected to the rising peripheral wall portion to an inner end portion connected to the depressed peripheral wall portion, and a height from the ground contact portion to the inner end portion of the movable wall portion is 45% or less of a height from the ground contact portion to the outer end portion of the movable wall portion. 